VANCOUVER, British Columbia, Jan. 17 (UPI) — Activists disrupted a speech by the leader of Canada’s Liberal party, protesting his position on development of the country’s oil sands, authorities said.

Tarsands are a mixture of sand or clay with a heavy form of crude oil, which can be extracted.

Michael Ignatieff was addressing a town hall meeting at the University of British Columbia when Greenpeace protesters started chanting and displaying signs, Canwest news service reported Sunday.

About a dozen activists began chanting “When I say ‘Stop the,’ you say ‘Tarsands’; Stop the Tarsands!” Canwest said.

The protesters said they want the Canadian government to halt development of Alberta’s oil sands, they said. Ignatieff, whose speech was halted for about two minutes, seemed not bothered by the protest, the report said.

“One of the key things about politics, one of the key things about Canada, is that we can’t pick and choose which facts we like. The tarsands are a fact of our national lives. We have one of the largest proven carbon oil reserves in the world,” he said.

“If you’re asking me to shut down the tarsands, it’s not in my power to do so, and frankly, it’s not in the national interest of our country to do so,” he added while the audience of about 400 applauded, Canwest reported.